Your question raises a range of regulatory issues and we don’t have enough information to provide a complete answer. You should obtain legal advice about your specific circumstances. You need to be quite careful when marketing a business that hasn’t been established yet, especially when it may require an AFSL but does not yet have one.
You will need an AFSL before you can provide any type of financial product advice. Financial product advice is any “recommendation or statement of opinion, or a report of either of those things, that is intended to influence a person or persons in making a decision in relation to a particular financial product or class of financial products…or could be reasonably be regarded as being intended to have such an influence.” (s766B(1) of the Corporations Act).
Most marketing of financial products and services falls within the scope of financial product advice – after all, the advertising wouldn’t be very effective if it didn’t influence people to purchase the financial product. So if your website will include any type of financial product advice, you will need an AFSL. You will also need to make sure that your website meets all of your other obligations, such as not being misleading or deceptive and meeting all your privacy obligations (if you are collecting personal information).